1. Field of the Invention
The present invention relates to a ball screw device, and more particularly to a ball screw device having a lubrication indicating or warning device for generating an indicating or warning signal when the lubrication for the balls or the bearing members or between the ball nut and the screw shaft has become fail or when the lubricating oil may not be suitably supplied to the balls or the bearing members or between the ball nut and the screw shaft.
2. Description of the Prior Art
Typical ball screw devices comprise a ball nut rotatably and/or moveably engaged onto a screw shaft, and normally arranged to allow the ball nut to be rotated and/or moved relative to the screw shaft in great rotational speeds. For allowing the ball nut to be smoothly rotated and moved relative to the screw shaft, a suitable bearing device or lubricating structure is further required to be provided and engaged between the ball nut and the screw shaft, for facilitating the rotational movement between the ball nut and the screw shaft.
For example, U.S. Pat. No. 5,809,829 to Seto et al. discloses one of the typical ball screw devices including a ball nut rotatably and/or moveably engaged onto a screw shaft to allow the ball nut to be rotated and/or moved relative to the screw shaft in great rotational speeds.
However, no lubricating oil has been disclosed and supplied to the balls or the bearing members or between the ball nut and the screw shaft such that a great heat may be generated between the ball nut and the screw shaft when the ball nut is rotated relative to the screw shaft in great rotational speeds.
U.S. Pat. No. 6,364,058 to Nishide et al. discloses another typical ball screw device including a lubricant supply device or an oil supplying structure for supplying oil or lubricant to lubricate the ball nut and the screw shaft and for eliminating the mounting and removal of the oil supplying device.
However, the lubricating oil may be consumed after use and the lubricating oil may not be suitably seen or knew by the users, and/or the consumption of the lubricating oil may not be aware by the users, such that the users may not know when to refill the lubricating oil.
U.S. Pat. No. 6,451,744 to Chang discloses another typical ball screw device or bushing assembly including a bushing or sleeve slidably engaged onto a spindle, and an inbuilt lubricating member or a lubricating collar is solidly attached onto the sleeve for lubricating purposes.
However, similarly, the lubricating oil may also be consumed after use and may not be seen or knew by the users, and/or the consumption of the lubricating material or the lubricating collar may not be aware by the users, such that the users may not know when to change or to replace the lubricating collar.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ball screw devices for such as machine tools or the like.